Creating axis builders

Author: yasuomaidana

plotly/src/layout/mod.rs

@@ -597,6 +597,14 @@ impl Axis {
         self.domain = Some(domain.to_vec());
         self
     }
+
+    pub fn single_axis(axis: Axis)->Vec<Option<Box<Axis>>>{
+        vec![Some(Box::new(axis))]
+    }
+
+    pub fn from_axes(axes: Vec<Axis>) -> Vec<Option<Box<Axis>>> {
+        axes.into_iter().map(|axis| Some(Box::new(axis))).collect()
+    }
 }
 
 #[derive(Serialize, Debug, Clone)]
@@ -2872,6 +2880,20 @@ mod tests {
         assert_eq!(to_value(annotation).unwrap(), expected);
     }
 
+    #[test]
+    fn test_single_axis_builder(){
+        let single_axis = Axis::single_axis(Axis::new());
+        let expected = json!([{}]);
+        assert_eq!(to_value(single_axis).unwrap(), expected);
+    }
+
+    #[test]
+    fn test_axes_builder(){
+        let axes = Axis::from_axes(vec![Axis::new(), Axis::new()]);
+        let expected = json!([{}, {}]);
+        assert_eq!(to_value(axes).unwrap(), expected);
+    }
+
     #[test]
     #[rustfmt::skip]
     fn test_serialize_click_mode() {